Mutations from wild-type which are I've listed are only those already named. While there are obviously some mutations from wild-type in both form and shape in some, there has been little work on such stuff, and almost nothing is known of their inheritance or even of their existance.

Saxon Swallow - blue white bar
Toy stencil; possibly pale; muff; crest - shell;
piebald (some very preliminary testing in my own loft indicated
"swallow" marking may be an allele of Baldhead)
Lahore - black                                                      Lahore - Lavender
Muff; Spread; unknown piebald; testing has indicated that the "Lahore marking" is actually three markings put together; a shield marking (colored wing shields); a head spot; and the neck marking. Selection for full coverage has led to the Lahore. The "Lavender" Lahore is identical in makeup to the Black but, in addition, it is also homozygous for milky.  There is still work being done on discovering exactly what is going on in this extremely striking breed.

Gimple -Dark Bronze Black Wing
(Also known as Archangel)
Genetic mutants immediately visible in bird::
gimpel bronze: T-pattern Check; crest - peak; grease quills
From just looking at this bird, I'd also say it has grease quills
- a special type of feather along its flanks which produce an
oil that makes the feathers shine. (Beside, I used to raise gimples and
I know they have them.)

Recessive red; muff; rose (beak-crest); crest - shell;
bronze (evidence is beginning to accumulate that one of the bronzes may be necessary to produce the whiteside pattern in recessive reds. Here, too, I'd also say it has grease quills. Just look at the shine on those feathers.
All photos except Lavender Lahore are courtesy of: Taeubers - Home - Page
The Lavender is courtesy of secretary of The British Lahore Club